Grinding machine



Oct. 22, 1929.

F. M. KERN GRINDING MACHINE Original Filed Feb. 3, 1926 gna-muto@ Ufer] M. )fern atto/r mq Patented Oct. 22, 1929 UNITED STATES PATENT OFFICE FRED M. KERN, 0F DETROIT, MICHIGAN, ASSTGNOR, BY MESNE ASSIGNMENTS, TO CIN- CINNATI GRINDERS INCORPORATED, OF CINCINNATI, OHIO, A CORPORATION OF OHIO GRINDING MACHINE Application filed February 3, 1926, Serial No. 85,790. Renewed March 1, 1929.

This invention relates to grinding machines for grinding successive pieces of work to a uniform predetermined size, and more particularly to machines for grinding short cylindrical or shouldered work wherein the work is positioned for rotation and grinding between a rapidly rotated grinding wheel and a slowly rotated work regulating wheel.

One of the objects of the invention is to provide a machine of the above nature which is capable of a wide range of use. Another object is to provide a machine of the above nature which is thoroughly practical and efficient.

Another object is to provide a centerless grinding machine capable of accurately and rapidly grinding work which is not uniformly cylindrical throughout its length, and capable of convenient adjustment to meet the varying requirements of such grinding.

It is a further object of the invention to provide a precision grinding machine with an adjustable mechanism so that it may be easily adapted foi' grinding `successive pieces of relatively short work to any predetermined size without removing and replacing any part of the mechanism.

lt is further object of the invention to provide a centerless grinding machine in which either the grinding wheel or the regulating wheel may be moved towards and away from the other wheel to grind successive work pieces to a substantially uniform predetermined size, and which is so constructed and arranged that the total travel of the movable wheel may be as large as possible for roughing cuts, or very small for finishing cuts.

lt is a still further object of the invention to provide a mechanisnnin a machine for grinding successive work pieces to a predetermined uniform size by periodically moving one of the wheels an invariable distance rapidly into approximate contact with the work, the work being then slowly ground, which may be adjusted to control the travel of the periodically moving wheel to obtain a desired depth of cut upon the work and at the same time always maintain the same general cyclic movement of the moving wheel relative to the work.

In one of the possible embodiments ofthe invention I provide a grinding machine having an adjustable mechanism which may be set to obtain a relative movement of any desired invariable amount between the grinding wheel and the work to grind successive work pieces uniformly to a predetermined size. This mechanism may be embodied in any type of grinding machine, such as a machine for grinding cylindrical work in which the work is held on centers; but is particularly applicable to a centerless grinding machine in which a workpiece is positioned between a rapidly rotated grinding wheel and a slowly rotated work regulating wheel which are arranged as in any of the well known types of centerless grinding machines. Preferably. the workis maintained in rotative Contact with the regulating wheel and either the grinding wheel or the regulating wheel may be moved relatively to the other wheel to cause the grinding wheel to grind successive work pieces uniformly to any predetermined size as desired. My preferred practice is to mount the grinding wheel rotatively in an eccentric trunnion which may be turned to feed the wheel towards and from the work. The trunnion may be oscillated cyclically by means, for example, of a positively rotated cam which is operatively connected with the truimion by a mechanism which may be adjusted to modify the effective action of the cam and thereby turn the trunnion through a greater or less distance. This may comprise an arm extendingr laterally from the trunnion which is moved by the cam through an intermediate pivoted lever and an adjustable mel ber arranged to move the trunnion in response to the movement of any point on the lever.

The invention accordingly consists in the features of construction1 combinations of elements, and arrangements of parts as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing in which is shown one of the various possible embodiments of this invention,`

Figure l is a partial side elevational view, partly in section, of a centerless grinding machine adapted for grinding short or shouldered work;

Fig. 2 is an elevational view part-ly in section of certain mechanisms embodied in the machine shown in Fig. 1; and

Fig. 3 is a partial plan view of a section through the grinding wheel spindle.

Similar reference characters refer to similar parts throughout the several views of the drawing.

l/Vhile the invention will be described by reference to its application to a centerless grinding machine, nevertheless it is not so limited as will be understood readily by those skilled in the art, and is equally applicable to any precision grinding machine wherein it is desirable to obtain a relative movement between the grinding wheel and the work to grind successive work pieces uniformly to a predetermined size. The machine illustrated comprises a frame having a hollow cylindrical portion 11 within which a column 12 is mounted for vertical movement. The column 12 is prevented from turning in the portion 11 by a key 13 engaging a groove 14 in the column. A spindle 15 carrying a regulating wheel 16 is mounted for rotation in suitable bearings (not shown) within the bearing casing 17 upon the support 18 integral with or suitably secured upon the top of the column 12, and is rotated relatively slowly from any suitable source of power', such as a motor (not shown), transmitted through the shaft 19 carrying a worm 2O which engages a worm wheel 21 secured upon the spindle 15.

A11 upwardly extending bracket 22, formed as an integral part of the column 12, is provided with slide ways 23 for a slide 24 having two horizontally extending arms 25 and 26 on each side of the machine. A work holding member or blade 27 is adjustably mounted upon the arm 25 by means of bolts 28 passing through slots 29 in the blade. A bracket 30 is provided with a pair of tongues 31 engaging slots 32 in the arms 26, and is adj ustably mounted thereon by means of bolts 33 passing through slots 34 in the arms. A front work holding member or blade 35 is adjustably mounted in the bracket 30 by means of bolts 36 passing through slots 37 in the blade. In the form of machine shown in the drawing the work '1.0 is positioned upon the regulating wheel 16 and maintained in a proper grinding position by the rear blade 27. The rear and front blades 27 and 35 respectively m be adjusted vertically simultaneously by turning a shaft 38 mounted in the bracket 22 and carrying a pinion 39 engaging a rack 40 on the slide 24.

A water pan 41 is secured to the column 12 by means of bolts 42 passing from the column into the support 18. The regulating wheel 1G and the bracket 22, as well as the water pan 411 may be moved vertically by turning a screw shaft 43, which is mounted, so as to prevent longitudinal movement, in a. bearing 44 in the column l2 and is arranged to engage a threaded hole 45 in a boss 46 secured to or integral with the frame 10. The screw shaft 43 may be turned by means of a hand wheel (not shown) secured upon a shaft 47 carrying a worm 48 which engages a worm wheel 49 mounted upon the screw shaft 43.

Referring now to the grinding wheel mounting', I preferably mount the wheel on a spindle carried in a hollow trunnion which is mounted for oscillatory movement in a bearing surface 56 in the frame 10. Eccentrically carried in the trunnion are bearings 57, shown as split tapered bearings, which may be suitably constructed as is well known in the art, and in which the grinding wheel spindle 58 is mounted for rotation. A grinding wheel 60 is suitably secured upon one tapered end ofthe spindle 58 as by means of a key G1 and a nut 62. A pulley 63 driven in any suitable manner, as by means of a belt (i4, may be secured at the other end of the spindle 58 for rotating the same.

The character of the eccentric mounting of the spindle 58 within the trunnion 55 is clearly illustrated in Fig. 2. The center of the trunnion indicatedby the intersection of the lines A and C, and the center of the spindle 58 is indicated by the intersection of lines A and B. It will be apparent that as the trunnion 55 is turned, the spindle 58 and the grinding wheel 60 will be moved towards and away from the regulating wheel 16 by pivoting about a point located at the inter'- section of the lines A and C.

My preferred mechanism for turning the trunnion 55 includes an arm 68 extending rearwardly from the trunnion as an integral part thereof and .having a follower 69 adjustably mounted within a slot 70 in the arm by means of an adjilsting screw 71. rfhe follower 59 is held downwardly by means of a weight 72 suspended from the end of the arm 68 by a rod 7 3, and is thereby maintained in contact with the plane bearing surface 74 on an arm or lever 75 which is pivoted at one end to turn about a shaft 7 6 and is provided at its other end with a cam follower 77 adapted to ride upon the peripheral surface of a cam 78 secured upon a rotatably mounted shaft 7 9. The shaft 7 9 may be rotated in the direction indicated by the arrow in Fig. 2 by means of a worm 80, secured upon a shaft 81 and engaging a worm wheel 82 secured upon the shaft 79. The shaft 81 may be driven from any appropriate source of power, and may be connected, for example, with a rotatably driven shaft 83 by means of a belt 84 passing over pulleys 85 and 86 mounted respectively on shafts 81 and 83.

rlhe machine may be adjusted for grinding work of any desired size by moving the regulating wheel 16 up or down to an appropriate position by turning the hand wheel (not shown) secured upon the shaft 47 carrying the worm 48. The rear blade 27 and the front blade 35 are then moved vertically to an appropriate position between the wheels to properly position the work upon the lower wheel 16 by turning the shaft 38 and the worm 39 to raise the slide 24 an appropriate amount. r1`he bolts 28 are then unloosened so that the work holding member 27 may be moved in a horizontal .direction to a proper position. The front guide blade 35 may be moved in a .horizontal direction to an appropriate position by uiiloosening the bolts 33 and sliding the bracket 30 along the slots 32 in the arms 26, and further horizontal adjustments may be obtained by unloosening the bolts 36 to permit movement of the blade relative to the bracket. y f

Power is then supplied from any appropriate source to turn the shaft 19 and move the belts 64 and 84 to rotate, respectively, the regulating wheel 16 relatively slowly and the grinding wheel 60 rapidly in the directions indicated respectively by the arrows in F ig. 1, and to impart a continuous rotary movement to the shaft 79 and the cam 78. The action of the cam 78 causes the arm 75 to oscillate so as to move the follower 69 and the arm 68 up and down to turn the trunnion 55, and thereby cause the spindle 58 and the grinding wheel 60 to move towards and away from the regulating wheel 16 and the work w which is supported between the two wheels. It will be apparent that the grinding wheel 60 may be caused to move towards and away from the regulating wheel 16 through any predetermined invariable distance, ldepending upon the position of the follower 69 upon the bearing surface 74 of the pivoted arm 75. rlhus, by turning the adjusting screw 71, the follower 69 may be moved along the surface 7 4 to a point directly above the cam follower 77 and thereby impart the full and complete action of the cam 78 to turn the trunnion 55 and move the grinding wheel 60 a relatively long distance towards and away from the regulatingl wheel; or the follower 69 may be moved along the surface 74: to a point directly above the center ofthe shaft 76 and thereby substantially negative the aetion of the cam 78; or the follower 69 may be moved along the surface 74 to an intermediate point so as to cause movement of the trunnion to move the grinding wheel towards and away from the regulating wheel a relatively short distance, or an amount satisfactory for finish grinding.

Preferably the cam 78 is so shaped and so positioned upon the shaft 79 as to impart an upward movement to the follower. 69' to turndthe trunnion 55 and move the grinding wheel 60 rapidly into approximate contact with the work w and then relatively slowly to grind the work to finished size and permit the grinding wheel to dwell and grind itself out.

In accordance with the provisions of the invention a precision grinding machine may be adjusted readily to cause either a relatively great or relatively small movement between the grinding wheel and the work being ground, depending upon whether it is desired to use the machine for rough or finish grinding. This may be accomplished readily without changing or removing any part of the mechanism.

The terms regulating wheel and slowly rotated regulating wheel are to be construed in the new commonly accepted understand-- ing of those skilled in the centerless grinding art. The speeds of both the grinding wheel and the regulating wheel must necessarily be varied in accordance with the type and nature of the work to be ground as well as the particular operation to be performed. The grinding wheel is to be rotated at a speed found suitable for grinding the work and the regulating wheel is to be given such a speed that the work will rotate during the grinding operation at that rate which is found desirable for the particular operation to be performed. lVithout reference to the theory of operation, the regulating wheel serves to 'control the speed of the work and the work may be given a faster or slower speed by increasmg or decreasing the speed of the regulating wheel respectively; by the speed of the work is meant the rate of rotation of the work.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what l claim as new and desire to secure by Letters Patent is:

1. A piecision grinding machine comprising a rapidly rotated grinding wheel, means for holding work rotatively during grinding, power driven means for periodically moving the work and the grinding wheel relatively towards and away from each other through an invariable distance to grind the work to a predetermined size, and means for adjusting the extent of said relative movement.

2. A grinding machine comprising a rapidly rotated grinding wheel, a slowly rotated work regulating wheel, means for holding work in operative position between said wheels, and a cam controlled mechanism for moving one of the wheels towards and away from the other through an invariable distance including a trunnion for eccentrically mounting the movable wheel, and means for lli) llo

changing the action of the cam effective for turning the trunnion to change the distance of' travel ot the movable wheel.

3. A grinding machine comprising a rapidly rotated grinding wheel and a slowly rotated work regulating wheel, means for holding work in operative position between said wheels7 and a cam controlled mechanism tor moving one ot the wheels towards and away trom the other an invariable distance including a trunnion ttor -eceentrically mounting the movable wheel, pivoted lever arranged to be actuated by the cam, and means responsive to the movement ot any point on the lever for actuating the trunnion to move said wheel through either a long or a short distance.

t. A grinding machine comprising a slowly rotated work regulating wheel, means to hold work in position to be engaged and rotated thereby, a trunnion, a grinding wheel spindle eccentrically mounted therein tor rotation, a grinding wheel on the spindle, a rotatably mounted cam, a pivoted lever operatively associated with the cam, and a follower adjustably mounted on the trunnion and adapted to engage the lever at any desired point so as to move the grinding wheel either a long or a short distance.

A grinding machine comprising a rapidly rotated grinding wheel, a slowly rotated work regulating wheel mounted below the grinding wheel, means :tor moving one of the wheels towards and away :trom the other an invariable distance, means ttor holding work in rotative contact with the regulating wheel and in position to be engaged by the grinding wheel., a` rotatably mounted cam, and adjustable connections between said cam and movable wheel adapted to move the wheel towards and away trom the other cyclically but through a variable and predetermined distance.

(i. ln grinding apparatus. in combination, a grinding throat adapted tor simultaneous grinding and rotating action upon work of round section and including at least three members one ot which members is in the term of a grinding wheel adapted to be rotated at relatively high speed, another ot said members being in the torni oi" a regulating wheel adapted to be rotated at a relatively low speed` and the third being a member tor holding work ot round section in operative relation to said two wheels, one ot said members being movable to change the relation ot the grinding throat to the work; means including an eccentric tor moving said movable member; and mechanism adapted upon actuation to operate .said eccentric, said mechanism including` a controllable connection therebetween and said eccentric adapted to permit variation ot the action ot said eccentric in response to said mechanism.

7 In grinding apparatus, in combination,

a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and including at least three members one ot which members is in the form ot a grinding wheel adapted to be rotated at relatively high speed, another oit said members being in the torni of a regulating wheel adapted to be rotated at a relatively low speed, and the third being a member for holding work ot round section in operative relation to said two wheels, one of said members being movable to change the relation of the grinding throat to the work; means including an eccentric for moving said movable membr; a lever; means for oscillating said lever; and means for connecting said eccentric to said lever, said connecting means being controllable to permit variation of the distance ot the point of connection from the il'ulcrum of said lever.

8. ln grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work ot round section and including at least three members one ot which members is in the form ot a grinding wheel adapted to be rotated at relatively high speed, another of said members being in the form of a regulating wheel adapted to be rotated at a relatively low speed, and the third being a member tor holding` work of round section in operative relation to said two wheels, one of said members being movable to change the relation ol the grinding throat to the work; a pivoted lever adapted for oscillation about its pivot; and means forming a connection between said lever and said movable member for moving the latter; and means for varying at will the distance of the point of connection 'of said connecting means to said lever from the pivot of the latter.

9. ln grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work of round section and including at least three members one o'll which members is in the 't'orm ot a grinding wheel adapted to be rotated at relatively high speed, another of said mem bers being in the form of a regulating wheel adapted to be rotated at a relatively low sneed, and the third being a. member iter holclino' work of round section in operative relatioii to said two wheels, one of said members being movable to change the relation ot the grinding throat to the work; a pivoted lever; a cam tor oscillating said lever about its pivot; and means Operated by said lever for moving said movable member and havin@l means whereby the effective arm of said levei may be changed.

10. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon work ot round section and including at least three members one of which members is in the form lll() of a grinding Wheel adapted to be rotated at relatively high speed, another of said members being in the form of a regulating Wheel adapted to be rotated at a relatively low speed, and the third being a member for holding Work of round section in operative relation to said two Wheels, one of said members being movable to change the relation of the grinding throat to the Work, a pair of levers related to each other and having connecting means such that as the effective arm of one is lengthened the effective arm of the other is shortened; means responsive to movement o one of said levers for moving said movable member; and means for actuating the other lever.

l1. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon Work of round section and including at least three members one of Which members is in the form of a grinding Wheel adapted to be rotated at relatively high speed, another of said members being in the form of a regulating ivheel adapted to be rotated at a relatively low speed, and the third being a member for holding Work of round section in operative relation to said two Wheels, one of said members being movable to change the relation the grinding throat to the wor a pair of levers related to each other and having connecting means such that as the effective arm of one is lengthened the effective arm of the other is shortened; means responsive to movement of one of said levers for moving said movable member; and means for oscillating the other lever between predetermined limits.

12. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon Work of round section and including at least three members one of Which members is in the form of a grinding Wheel adapted to be rotated at relatively high speed, another of said members being in the form of a regulating Wheel adapted to be rotated at a relatively 10W speed, and the third being a member for holding Work of round section in operative relation to said two Wheels, one of said members being movable to change the relation of the grinding throat to the Work, a pair of levers related to each other and having connecting means such that as the effective arm of one is lengthened the effective arm of the other is shortened; means responsive to movement of one of said levers for moving said movable member; and a cam for oscillating the other lever.

13. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon Work of round section and including at least three members one of which members is in the form of a grinding Wheel adapted to be rotated at relatively high speed, another of said members being in the form ot a regulating Wheel adapted to be rotated at a relatively low speed, and the third being a member for holding Work of round section in operative relation to said two Wheels, one of said members being movable to change the relation of the grinding throat to the Work, a pair of levers related to each other and having connecting means such that as the effective arm of one is lengthened the eective arm of the other is shortened; an eccentric responsive to the movement of one of said levers for moving said movable member; and means for actuating the other lever.

14. In grinding apparatus, in combination, a grinding throat adapted for simultaneous grinding and rotating action upon Work of round section and including at least three members one of Which members is in the form of a grinding Wheel adapted to be rotated at relatively high speed, another of said members being in the form of a regulating Wheel adapted to be rotated at a relatively low speed, and the third being a member for holding Work ot round section in operative relation to said tWo Wheels, one of said members being movable to change the relation of the grinding throat to the Work; a cam; means actuated by said cam and having portions moving throughout dilferent distances; and means for connecting said movable member selectively to any one or" said portions of said actuated means.

Signed at Detroit, Michigan, this 30th day of January, 1926.

FRED M. KERN. 

